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NVD / CVE Program· CNA VulnCheck

CVE-2026-58050: libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation

HighCVSS 8.3 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 33/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.44% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: azl3 rust 1.96.1-1 on Azure Linux 3.0 1.96.1-2.

Low priority for now. Upgrade to azl3 rust 1.96.1-1 on Azure Linux 3.0 1.96.1-2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.

Published
Jun 28, 2026
Updated
Oct 25, 2026
EPSS
0.4% · 39th percentile

Report tools

JSON

Action score

33

Monitor

Low priority for now.

CVSS
33 / 40 · 8.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
7.0
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Follow CVE-2026-58050

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
libssh2libssh2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • libssh2 libssh2

    • up to and including 1.11.1affected · semver

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • libssh2 libssh2up to 1.11.1 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.21libssh2before 1.11.1-r31.11.1-r3
Alpine:v3.23libssh2before 1.11.1-r41.11.1-r4
Debian:12libssh2before 1.10.0-3+deb12u11.10.0-3+deb12u1
Debian:13libssh2before 1.11.1-1+deb13u21.11.1-1+deb13u2
Debian:14libssh2before 1.11.1-61.11.1-6
openSUSE:Leap 16.0libssh2_orgbefore 1.11.1-160000.5.11.11.1-160000.5.1
openSUSE:Tumbleweedlibssh2_orgbefore 1.11.1-4.11.11.1-4.1
Red Hat:hummingbird:1libssh2before 0:1.11.1-10.4.hum10:1.11.1-10.4.hum1
Red Hat:hummingbird:1libssh2-develbefore 0:1.11.1-10.4.hum10:1.11.1-10.4.hum1
Red Hat:hummingbird:1libssh2-docsbefore 0:1.11.1-10.4.hum10:1.11.1-10.4.hum1
Red Hat:rhel_els:7libssh2before 0:1.8.0-4.el7_9.20:1.8.0-4.el7_9.2
Red Hat:rhel_els:7libssh2-develbefore 0:1.8.0-4.el7_9.20:1.8.0-4.el7_9.2
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSlibssh2_orgbefore 1.11.0-150000.4.35.11.11.0-150000.4.35.1
SUSE:Linux Enterprise Micro 5.3libssh2_orgbefore 1.11.0-150200.9.8.11.11.0-150200.9.8.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7libssh2_orgbefore 1.11.0-150600.20.6.11.11.0-150600.20.6.1
SUSE:Linux Enterprise Server 12 SP5-LTSSlibssh2_orgbefore 1.11.0-29.18.11.11.0-29.18.1
SUSE:Linux Micro 6.0libssh2_orgbefore 1.11.0-4.11.11.0-4.1
SUSE:Linux Micro 6.1libssh2_orgbefore 1.11.0-slfo.1.1_2.11.11.0-slfo.1.1_2.1
SUSE:Linux Micro 6.2libssh2_orgbefore 1.11.1-160000.5.11.11.1-160000.5.1

Same product

libssh2: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-3861An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH packets with a padding length value greater than the…
    38Monitor
  • CVE-2019-3860An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SFTP packets with empty payloads are parsed.
    38Monitor
  • CVE-2019-3858An out of bounds read flaw was discovered in libssh2 before 1.8.1 when a specially crafted SFTP packet is received from the server.
    38Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-55200Jun 17, 2026 · libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c
    37Monitor
  • ← EarlierCVE-2025-15661Jun 18, 2026 · libssh2 - Heap Buffer Over-read via sftp_symlink() in sftp.c
    33Monitor
  • Later →CVE-2026-58051Jun 28, 2026 · libssh2 - Free of Uninitialized Pointer in publickey List Cleanup
    33Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
azl3 rust 1.96.1-1 on Azure Linux 3.01.96.1-2Microsoft (MSRC)
alpine:libssh21.11.1-r3 · Alpine:v3.21Package registry (OSV)
alpine:libssh21.11.1-r4 · Alpine:v3.24Package registry (OSV)
debian:libssh21.10.0-3+deb12u1 · Debian:12Package registry (OSV)
opensuse:libssh2_org1.11.1-4.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:libssh20:1.11.1-10.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libssh2-devel0:1.11.1-10.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libssh2-devel0:1.8.0-4.el7_9.2 · Red Hat:rhel_els:7Package registry (OSV)
red hat:libssh2-docs0:1.11.1-10.4.hum1 · Red Hat:hummingbird:1Package registry (OSV)
suse:libssh2_org1.11.1-160000.5.1 · SUSE:Linux Micro 6.2Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Not on record for this CVE: EPSS history · patch commit or PR link · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-190 · Integer Overflow or Wraparound

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records